1. Field of the Invention
The application relates to a pixel structure and a fabricating method thereof. More particularly, the application relates to an organic electro-luminescence display unit and a fabricating method thereof.
2. Description of Related Art
An organic electro-luminescence device is characterized by self-luminance, high brightness, high contrast, wide view angle, fast response speed, and so on. Therefore, among various displays, an organic electro-luminescence display panel frequently draws attention. In general, the organic electro-luminescence display panel can be classified into a top emission organic electro-luminescence display panel and a bottom emission organic electro-luminescence display panel, wherein the latter is more common.
FIGS. 1A to 1G are schematic cross-sectional views illustrating a fabricating process of a conventional organic electro-luminescence display unit. As indicated in FIG. 1A, a substrate 100 is provided, and a first photolithography and etching process (PEP) is performed to form a gate 110 on the substrate 100. Next, a gate insulating layer 120 is formed on the entire substrate 100 to cover the gate 110.
After that, as shown in FIG. 1B, a second PEP is performed to form a patterned semiconductor layer 130 on the gate insulating layer 120. Here, the patterned semiconductor layer 130 is located above the gate 110.
Thereafter, as indicated in FIG. 1C, a third PEP is performed to form a source 140S and a drain 140D on a portion of the patterned semiconductor layer 130 and a portion of the gate insulating layer 120. The source 140S and the drain 140D are electrically insulated from each other and located at respective sides of the patterned semiconductor layer 130.
In FIG. 1D, a passivation layer 150 is then formed to cover the source 140S, the drain 140D, the portion of the patterned semiconductor layer 130 uncovered by the source 140S and the drain 140D, and the portion of the gate insulating layer 120 uncovered by the source 140S and the drain 140D. It can be observed from FIG. 1D that the passivation layer 150 has a contact 150a exposing a portion of the drain 140D.
Afterwards, as indicated in FIG. 1E, a pixel electrode 160 is formed on the passivation layer 150. Here, the pixel electrode 160 is electrically connected to the drain 140D through the contact 150a. In the conventional bottom emission organic electro-luminescence display unit, the pixel electrode 160 is usually made of transparent conductive oxide (TCO), e.g., indium-tin oxide (ITO), indium-zinc oxide (IZO), and so forth.
Next, with reference to FIGS. 1F and 1G, after the pixel electrode 160 is formed, an organic electro-luminescence layer 170 and a top electrode 180 are sequentially formed. The top electrode 180 of the conventional bottom emission organic electro-luminescence display unit is often made of metal. When a driving current is applied to the organic electro-luminescence layer 170 located between the pixel electrode 160 and the top electrode 180, most light emitted from the organic electro-luminescence layer 170 passes through the substrate 100.